(1) Field of the Invention
This invention relates to a process for preparing an acrylate compound which is expected to be used as a raw material for functional polymers, pharmaceuticals and pesticides.
(2) Description of the Related Art
In recent years acrylate compounds have provided a great attraction, for example, as monomers used for producing a resist for advanced semiconductor lithography. Especially acrylate compounds having a tertiary ester skeletal structure capable of being dissociated with an acid are suitable therefor in view of lithography mechanism.
As specific examples of the acrylate or methacrylate compounds having such a skeletal structure capable of being dissociated with an acid, there can be mentioned acrylates and methacrylates having an acid-dissociatable group such as a 2-methyl-2-adamantyl group or a 8-ethyl-8-tricyclodecanyl group (Japanese Unexamined Patent Publication [hereinafter abbreviated to xe2x80x9cJP-Axe2x80x9d) No. 2001-188352, JP-A H11-305444 and JP-A H9-43848), and xcex1-trifluoromethylacrylates having an acid-dissociatable group such as a 2-methyl-2-adamantyl group or a 1-alkyl-1-cycloalkyl group (JP-A 2001-302728).
The above-mentioned acrylate compounds are prepared, for example, by the following known processes.
A first type process comprises allowing an acrylic acid chloride compound to react with an alcohol or a metal alcoholate in the presence of a base. The first type process includes, for example, a process wherein 2-methyl-2-adamantanol is allowed to react with acryloyl chloride or methacryloyl chloride in the presence of triethylamine to give a corresponding acrylate or methacrylate compound (for example, JP-A H11-305444, JP-A 2000-122294, JP-A 2000-229911 and JP-A 2001-188352), and a process wherein 8-ethyl-8-cyclododecanol is allowed to react with methacryloyl chloride in the presence of triethylamine (JP-A 2001-188352). The first type process further includes a process wherein 2-adamantanone is allowed to react with methyllithium or a methyl Grignard reagent to give a Li or Mg salt of 2-methyl-2-adamantanonol, and then, methacryloyl chloride is added in a solution of the thus-obtained Li or Mg salt to give a corresponding methacrylate compound (JP-A H10-182552 and JP-A 2000-229911).
The first type process has a problem such that acryloyl chloride and methacryloyl chloride are not readily available and are expensive, and are difficult to handle because these acid chlorides easily produce a large amount of hydrogen chloride gas when they are contacted with moisture in the air.
As a process wherein acryloyl chloride and methacryloyl chloride are not used to overcome the first type process, a second process has been proposed which includes, for example, a process wherein acrylic acid is allowed to react with a tertiary alcohol such as 1-ethyl-1-cyclohexanol (JP-A 2000-319226).
However, in the second process, large amounts of a carboxylic acid anhydride such as acetic anhydride and an amine compound such as triethylamine must be used to smoothly carry out the reaction, with the result of reduction in efficiency and cost for production.
In view of the foregoing, a primary object of the present invention is to provide a process for preparing acrylate compounds whereby the object compounds can be prepared with high efficiency without the above-mentioned problems of the prior art, namely, with a reduced cost and an enhanced safety.
Thus, in accordance with the present invention, there is provided a process for preparing an acrylate compound represented by the following formula (4): 
wherein R1 and R2 independently represent a hydrogen atom or a fluorine atom, R3 represents a hydrogen atom, a fluorine atom, an alkyl group, an alkenyl group, a fluoroalkyl group, or a fluoroalkenyl group, R4 and R5 independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, a halogenated alkyl group, or a halogenated alkenyl group; and X and Y independently represent a hydrocarbon group, which may have at least one substituent selected from the group consisting of a halogen-containing substituent, an oxygen-containing substituent and a nitrogen-containing substituent, and dashed line - - - - - means that X and Y may be bonded together to form a cyclic structure;
which comprises allowing an acrylic acid compound represented by the following formula (1): 
wherein R1, R2 and R3 are the same as defined above for formula (4), to react with an unsaturated compound represented by the following formula (2) or (3): 
wherein R4, R5, X and Y are the same as defined above for formula (4).